title: Does change in definition of psychotic symptoms in diagnosis of schizophrenia in DSM-5 affect caseness?
abstract: Psychotic symptoms are a central element in the diagnosis of schizophrenia, although their precise definition has varied through the multiple iterations of DSM and the ICD. Schneiderian first-rank symptoms (FRS) have received a particularly prominent position in the diagnostic criteria of schizophrenia since ICD-9 and DSM-III. In the current iteration of DSM (DSM-IV-TR), whereas two characteristic symptoms are ordinarily required to meet criterion A, only a single symptom is necessary if the psychotic symptom happens to be a FRS, notably a bizarre delusion or auditory hallucination of a running commentary or 'conversing voices'. Because of limited data in support of the special treatment of FRS, DSM-5 has made changes to criterion A, requiring that at least two psychotic symptoms be present in all cases with at least one of these symptoms being a delusion, hallucination, or disorganized speech. To assess the impact of these changes on the prevalence of schizophrenia, we examined a research dataset of 221 individuals with DSM-IV schizophrenia to study the prevalence and co-occurrence of various criterion A symptoms. Although bizarre delusions and/or Schneiderian hallucinations were present in 124 patients (56.1%), they were singly determinative of diagnosis in only one patient (0.46%). Additionally, only three of the 221 patients (1.4%) with DSM-IV schizophrenia did not have a delusion, hallucination, or disorganized speech. DSM-5 changes in criteria A should have a negligible effect on the prevalence of schizophrenia, with over 98% of individuals with DSM-IV schizophrenia continuing to receive a DSM-5 diagnosis of schizophrenia in this dataset.
authors.affiliation: Department of Psychiatry, University of Florida Medical School, Gainesville, FL 32610-3424, USA. tandon@ufl.edu
authors.forename: Rajiv
authors.initials: R
authors.lastname: Tandon
authors.forename: Dawn
authors.initials: D
authors.lastname: Bruijnzeel
authors.forename: Babu
authors.initials: B
authors.lastname: Rankupalli
mesh_terms: D016208:Databases, Factual; D003702:Delusions / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006212:Hallucinations / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D015995:Prevalence; D011618:Psychotic Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D012720:Severity of Illness Index